Check-valve control means for pistons



.uy 3l; i923. y L46328 F. L. MUMFORD A C CHECK VALVE CONTROL MEANS FOR PISTONS Filed May 25, 1922 Till- 4 "1 vENT n.;

@Mm W' Patented duly 3l, i923.

' intatta FRANK L. ivLUivrronD, or TOLEDO, onto.

CHECK-VALVE CONTROL MEANS ron ris'rorisl Application filed May `25, 1922. Serial No. 563,656.

To all to hom 'may concern Be it known that I, FRANK L, MUMFORD, a citizen of the United States, and a resident of Toledo, in the county of Lucas and State of Ohio, have made an invention appertaining to a Check-Valve Control Means for Pistons; and l do hereby declarethe ifol-v lowing to be a full, clear, and exact description or" the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to fluid compressors, and particularly to those used in connection with refrigerating plants.

The object of the invention is the provision in connection with the customary piston valve of a compressor pump, of means which is automatically operable, independently of the fluid pressure on the valve, to open and close the valve to its full extent during the respective suction and compressing strokes of' the piston, thereby effecting more eiiicient and positive action of the valve than would otherwise vbe present and enhancing the practicability and commercial value of machines of this type.

The invention is fully described in the following specification, and while, in its broader aspect, it is capable of embodiment in numerous forms, a preferred embodiment thereof is illustrated in the accompanying drawings, in which,-

Figure 1 is a central vertical section of compressor embodying the invention with i parts in full and with the piston valve open. rig. 2 is an enlarged central longitudinal section of a piston embodying the invention with parts in full and the valve closed, and Figs. 3 and it are cross-sections, respectively, on the lines 33 and 4% in Fig. 2.

Referring to the drawings, 1 designates the cylinder of a fluid compressor of a type commonly used in compressing the refrigerant in a refrigerating apparatus, said cylinder having a gas intake passage 2 therein at a point below its upper end and an outlet passage 3 at its upper portion, which latter communicates with the upper end of the cylinder through one or more passages which are normally closed by a 'valve 4, as well understood in the art.

The piston in connection with which the invention is used has, in its present embodi! mont.l a head portion 5 and a foot portionp, which are rigidly connected by a plurality oi longitudinally extending websV 7 equidistantly spacedL around the pis-ton axis. The foot member 6 of the piston is connected by Ea rod 8 to ali-operating crank 9 disposed within the crank case of the compressor. The head portion 5 of the piston is provided with an Opening 10, which is formed at its upper end with a conical valve seat 11 within which a valve 12 is adapted/to seat to close the communication between the upper and lower `portions of thel cylinderthrough the piston head 5, the valve being adapted to seat during a compressing stroke oi the piston and to open during a suction stroke thereof. The yliuid intake 2 ot the cylinder opens into the space between the upper and lower portions 5 and 6 of the piston, saidy space being sufiiciently long to accommodate the stroke of the piston.

The stem 13 oit the valve 12 extends downv through a guide bearing 14, which is centrally disposed withinthc piston head 5 by radial ribs 15, and the lower end of the valve stem extends down to near the bottom portion 6 of the piston and is guided at its lower end by a bearing 16 carried bythe webs 7 through radial arms 17. The stem 13 has a spider 18 fixed thereto, in the present instance, adjacent to the lower end of the piston head 5, and the arms of the spider carry a compression ring 19. rlhis ring frictionally coacts with the side wall of the cylinder 1 the same as the rings 20 of the piston and during an upwardl or compression stroke of the piston the ring 19 drags against the cylinder wall to effect, first, a closing of the valve 12 and then tov cooperate with the pressure in the cylinder to hold the valve seated during the remainder of the stroke. Upon a down or suction stroke of the piston the ring 19 and connected valve remain stationary until the piston engages the spider 18 and forces it downward therewith, thus effecting first, an opening of the valve and then maintaining the valve open during the entire stroke, or until the movement of the piston is reversed, when the valve is again closed by reason of the frictional or dragging coaction of the ring 19 against the cylinder wall.

The opening movement of the valve 12 may be stopped by coaction of thespider 18 with the piston head, by the coaction lil!) of a stem, collar or shoulder 2l, against the bearing 16, or by any other means. lt is evident with my valve operating means that the opening and closing of ie valve arenot dependent on the pressure of the fluid against either the under or upper side thereof during the respective suction or compression strokes of the piston, but is occasioned by the frictional coaction of the cylindrical wall with the dragvring 19 car ried by thevr valve stem.

l wish it understood, that my invention is not limited to any specic construction, arrangement or form of the parts, as it is capable of embodiment in numerous forms without departing from the spirit of the claims.

Having 'thus described my invention, what I claim as new, and desire to secure by Letters Patent, is,

l. In combination, a cylinder, a piston mounted therein and having an opening longitudinally therethrough, a check valve seating in the piston opening and having a stem projecting therefrom through the piston and guided for limited reciprocatory movements longitudinally thereof,

and means carried by the valve stem for movements therewith, said means having a friction ring in sliding coaction with the cylinder Wall to cause an opening of the valve when the piston is moved in one direction and a closing of the valve when moved in the opposite direction.

2. ln combination, a cylinder having fluid intake passage and a fluid discharge passage in spaced relation longitudinally thereof, a piston movable in the cylinder between the passages and having a passage therethrough, `a check valve for seating in the piston passage and having stem extending through the piston and below the same andguided thereby for longitudinal movements, a spider carried by the stem below the piston, and a compressible friction ring carried by the spider arms at the outer ends thereof for 'frictional coaction with the cylinder wall to effect an opening oi the valve when the piston is moved in one direction and a closing ofthe valve when the piston is moved in the opposite direction.

ln testimony whereoic l have hereunto signed my name toy this specification.

FRANK L. MUMFORD. 

